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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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2024 ANS Annual Conference
June 16–19, 2024
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Nuclear Technology
Fusion Science and Technology
Latest News
Bipartisan Fusion Energy Act pushes for regulatory clarity
Sen. Alex Padilla (D., Calif.) introduced the Fusion Energy Act (S. 4151) last month with a bipartisan group of cosponsors—John Cornyn (R., Texas), Cory Booker (D., N.J.), Todd Young (R., Ind.), and Patty Murray (D., Wash.). The legislation would codify the Nuclear Regulatory Commission’s regulatory authority over commercial fusion energy systems to streamline the creation of clear federal regulations that will support the development of commercial fusion power plants—and would require a report within one year on a study of risk- and performance-based, design-specific licensing frameworks for “mass-manufactured fusion machines.
“Congress must do everything in its power to ensure continued U.S. leadership in developing commercial fusion energy facilities,” said Padilla as he introduced the bill. “The Fusion Energy Act would provide regulatory certainty for investors as the NRC develops and streamlines frameworks for such facilities.”
Eric Leclerc, Georges J. Berthoud
Nuclear Technology | Volume 144 | Number 2 | November 2003 | Pages 158-174
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT03-A3437
Articles are hosted by Taylor and Francis Online.
In hypothetical Severe Accident studies for a PWR, a large amount of molten corium may be poured into water. There is then a risk of Steam Explosion. After the premixing sequence in which the melt is more or less dispersed into water, a fine fragmentation process may start, which can lead to an escalation. Such an event is generally triggered by the destabilization of the vapor film surrounding the hot melt droplets. In this paper, an attempt to describe all the successive processes leading to this fine fragmentation is presented.First, a critical analysis of previous models is performed, allowing us to propose a new sequence of events. As in the previous models, the film destabilization leads to the growth of cold liquid peaks induced by Rayleigh Taylor instability. As these peaks have a smaller density than the drop, they do not penetrate into the hot drop. At the cold liquid-hot liquid contacts, transient heat transfer leads to the explosive boiling of a small amount of coolant. The generated local pressurization deforms the hot melt interface. This can produce fine fragments from the filaments issued from the melt. Some of them may reach the vapor-coolant interface where intense and rapid vaporization occurs. A large bubble then develops, and a new fragmentation sequence may again appear at the bubble collapse. The present model is supported by experimental results.